JP7340839B2 - Power element manufacturing equipment and power element manufacturing method - Google Patents

Description

The present invention relates to a power element manufacturing apparatus and a power element manufacturing method .

Conventionally, refrigeration cycles used in air conditioners installed in automobiles use thermal expansion valves with a built-in temperature-sensing mechanism that adjust the amount of refrigerant passing according to the temperature in order to save installation space and reduce piping work. has been done. The valve body of such an expansion valve has an inlet port into which high-pressure refrigerant is introduced and a valve chamber that communicates with the inlet port, and the top of the valve body is equipped with a drive mechanism for the valve member called a power element. be done.

The power element shown in Patent Document 1 is composed of an upper lid member that forms a pressure working chamber, a thin plate diaphragm that elastically deforms under pressure, and a disc-shaped receiving member, and the three members are overlapped to form a circumferential portion. It is formed by joining them by TIG welding or the like. Such power elements are used not only for expansion valves but also for constant pressure valves and the like.

Japanese Patent Application Publication No. 2017-58090

By the way, a working gas such as an inert gas is sealed at a predetermined pressure in a pressure working chamber formed by the upper lid member and the diaphragm of the power element. At this time, in order to seal the working gas into the pressure working chamber, a hole is provided at the top of the top cover member, and after filling the working gas through this hole, the hole is covered with a steel ball, etc., and the pressure working chamber is sealed by projection welding or the like. are doing.

However, in order to seal the pressure working chamber using the above method, manufacturing equipment including a projection welding machine is required, leading to an increase in the cost of the power element and the expansion valve.

In addition, after brazing a metal tube called a capillary into a hole formed in the upper lid member and injecting working gas through the capillary, the end of the capillary is sometimes closed; Brazing must be performed beforehand, which increases manufacturing man-hours.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a power element manufacturing apparatus and a power element manufacturing method that can manufacture a power element with a reduced number of manufacturing steps while using simple equipment.

In order to achieve the above object, a power element manufacturing apparatus according to the present invention is a power element manufacturing apparatus in which a diaphragm is sandwiched between a lid member and a receiving member,
A casing that can seal gas at a predetermined pressure inside and has an opening;
a light transmitting member that covers the opening;
a holding shaft that is disposed within the housing and holds the lid member, the diaphragm, and the receiving member in a stacked state;
a drive source that rotates the holding shaft;
a laser light source that performs welding by irradiating a laser beam from the outside of the casing to the overlapping portion of the lid member and the receiving member through the opening ,
The holding shaft has an upper shaft and a lower shaft arranged coaxially,
The upper shaft communicates with an upper shaft periphery that a peripheral edge of the lid member comes into contact with, an upper shaft recess formed at the center of the upper shaft periphery, and an outer periphery of the upper shaft and an inner periphery of the upper shaft recess. Has an upper shaft communication hole,
The lower shaft communicates with a lower shaft periphery that the peripheral edge of the receiving member contacts, a lower shaft recess formed at the center of the lower shaft periphery, and an outer periphery of the lower shaft and an inner periphery of the lower shaft recess. It is characterized by having a lower shaft communication hole .

Further, a method for manufacturing a power element according to the present invention is a method for manufacturing a power element in which a diaphragm is sandwiched between a lid member and a receiving member,
The upper shaft periphery has an upper shaft periphery that the periphery of the lid member comes into contact with, an upper shaft recess formed in the center of the upper shaft periphery, and an upper shaft communication hole that communicates the outer periphery of the upper shaft with the inner periphery of the upper shaft recess. an upper shaft, a lower shaft periphery with which a peripheral edge of the receiving member comes into contact, a lower shaft recess formed in the center of the lower shaft periphery, and a lower shaft communicating with the outer periphery of the lower shaft and the inner periphery of the lower shaft recess; holding the lid member, the diaphragm, and the receiving member in a stacked state in a housing using a lower shaft having a communication hole ;
Injecting gas at a predetermined pressure into the housing,
While rotating the lid member, the diaphragm, and the receiving member, welding is performed by irradiating the overlapped portion of the lid member and the receiving member from outside the housing with a laser beam, thereby welding the object to be welded. form,
The method is characterized in that the gas in the casing is exhausted and the workpiece to be welded is taken out from the casing.

According to the present invention, it is possible to provide a power element manufacturing apparatus and a power element manufacturing method that can manufacture a power element at low cost using simple equipment.

FIG. 1 is a schematic sectional view schematically showing an example in which the expansion valve according to the first embodiment is applied to a refrigerant circulation system. FIG. 2 is a cross-sectional view of the power element manufacturing apparatus in an exploded state. FIG. 3 is a sectional view of the power element manufacturing apparatus in an assembled state. FIG. 4 is a sectional view of a constant pressure valve including a power element according to a second embodiment. FIG. 5 is a sectional view of the power element manufacturing apparatus in an assembled state.

Embodiments according to the present invention will be described below with reference to the drawings.

(Definition of direction)
In this specification, the direction from the valve body toward the actuation rod is defined as "upward direction," and the direction from the actuation rod toward the valve body is defined as "downward direction." Therefore, in this specification, the direction from the valve body toward the actuating rod is referred to as the "upward direction" regardless of the orientation of the expansion valve or the constant pressure valve.

(First embodiment)
Referring to FIG. 1, an overview of an expansion valve 1 using a power element will be described. FIG. 1 is a schematic sectional view schematically showing an example in which the expansion valve 1 according to the present embodiment is applied to a refrigerant circulation system 100. In this example, expansion valve 1 is fluidly connected to compressor 101 , condenser 102 and evaporator 104 .

The expansion valve 1 includes a valve body 2 including a valve chamber VS, a valve body 3, a biasing device 4, an actuating rod (actuating member) 5, a ring spring 6, and a power element 8. Let L be the axis of the expansion valve 1.

The valve body 2 includes a first flow path 21 and a second flow path 22 in addition to the valve chamber VS. The first flow path 21 is a supply side flow path, and a refrigerant (also referred to as fluid) is supplied to the valve chamber VS via the supply side flow path. The second flow path 22 is a discharge side flow path, and the fluid in the valve chamber VS is discharged to the outside of the expansion valve via the operating rod insertion hole 27 and the discharge side flow path. The first flow path 21 and the valve chamber VS communicate with each other through a connecting path 21a having a smaller diameter than the first flow path 21.

The valve body 3 is arranged within the valve chamber VS. When the valve body 3 is seated on the annular valve seat 20 of the valve body 2, the first flow path 21 and the second flow path 22 are out of communication. On the other hand, when the valve body 3 is spaced apart from the valve seat 20, the first flow path 21 and the second flow path 22 are in communication.

The lower end of the actuating rod 5 inserted into the actuating rod insertion hole 27 with a gap is in contact with the upper surface of the valve body 3. Further, the actuating rod 5 can press the valve body 3 in the valve opening direction against the urging force of the urging device 4. When the actuating rod 5 moves downward, the valve body 3 separates from the valve seat 20, and the expansion valve 1 becomes open.

Next, the power element 8 will be explained. The power element 8 is attached to a recess 2a provided at the top of the valve body 2. The recess 2a communicates with a return passage 23 in the valve body 2, through which the refrigerant from the evaporator 104 passes, via a communication passage 2b. The actuating rod 5 passes through the communication path 2b.

The power element 8 includes an upper lid member (also referred to as a lid member) 82, a diaphragm 83, and a receiving member 86, and is used in combination with a stopper member 84.

The upper lid member 82 is formed by press-molding a plate material made of SUS, for example, and has a central dome portion 82a and a radial flange portion 82b that radially extends from the lower end of the dome portion 82a. The upper lid member 82 does not have a hole that communicates the upper and lower surfaces.

The diaphragm 83 is made of a thin metal plate on which a plurality of concentric concave and convex shapes are formed.

The receiving member 86 is formed by press-molding a plate material made of SUS, for example, and is connected to a flange portion 86a having an outer diameter that is approximately the same as the outer diameter of the flange portion 82b of the upper lid member 82, and to the center of the lower surface of the flange portion 86a. It has a hollow cylindrical portion 86b. The manufacturing process of the power element 8 will be described later.

The ring spring 6 is installed in a concave annular portion 26 of the valve body 2 in FIG. 1 . The ring spring 6 is a plate-shaped member formed by cutting and raising a plurality of elastic pieces, which is curved into a cylindrical shape so that the elastic pieces are on the inside.

The ring spring 6 having such a configuration functions to apply a pressing force from an elastic piece to the outer periphery of the actuating rod 5 passing inside.

Next, the urging device 4 will be explained. In FIG. 1, the biasing device 4 includes a coil spring 41 made of a circular wire wound spirally, a valve body support 42 that is attached to the upper end of the coil spring 41 and supports the valve body 3, and a lower end of the coil spring 41. The spring receiving member 43 is attached to the valve body 2 while supporting the valve body 2. The spring receiving member 43 has the function of sealing the valve chamber VS of the valve body 2 and supporting the end of the coil spring 41 that biases the valve body 3 toward the valve seat 20 .

The spherical valve body 3 is welded to the upper surface of the valve body support 42, and the two are integrated.

(Operation of expansion valve)
An example of the operation of the expansion valve 1 will be described with reference to FIG. The refrigerant pressurized by the compressor 101 is liquefied by the condenser 102 and sent to the expansion valve 1. Further, the refrigerant that has been adiabatically expanded by the expansion valve 1 is sent to the evaporator 104, where it exchanges heat with the air flowing around the evaporator. The refrigerant returning from the evaporator 104 passes through the expansion valve 1 (more specifically, the return passage 23) and is returned to the compressor 101 side.

High-pressure refrigerant is supplied to the expansion valve 1 from a condenser 102 . More specifically, the high-pressure refrigerant from the condenser 102 is supplied to the valve chamber VS via the first flow path 21.

When the valve body 3 is seated on the valve seat 20 (in other words, when the expansion valve 1 is in the closed state), the first flow path 21 on the upstream side of the valve chamber VS and the downstream side of the valve chamber VS The second flow path 22 is in a non-communicating state. On the other hand, when the valve body 3 is spaced apart from the valve seat 20 (in other words, when the expansion valve 1 is in the open state), the refrigerant supplied to the valve chamber VS flows through the operating rod insertion hole 27 and the It passes through the two flow paths 22 and is sent to the evaporator 104. Note that switching between the closed state and the open state of the expansion valve 1 is performed by an actuation rod 5 connected to the power element 8.

In FIG. 1, the power element 8 is provided with a pressure working chamber PA and a lower space LS partitioned by a diaphragm 83. Therefore, when the working gas pressure in the pressure working chamber PA decreases, the working rod 5 moves upward, and when the working gas pressure increases, the working rod 5 moves downward. In this way, the expansion valve 1 is switched between the open state and the closed state.

Furthermore, the lower space LS of the power element 8 communicates with the return flow path 23. Therefore, the pressure of the working gas in the pressure working chamber PA changes depending on the temperature and pressure of the refrigerant flowing through the return passage 23, and the working rod 5 is driven by the pressure difference. In other words, in the expansion valve 1 shown in FIG. be adjusted.

(Power element manufacturing equipment)
Next, a manufacturing apparatus for the power element 8 will be explained. FIG. 2 is a cross-sectional view of the power element 8 manufacturing apparatus 200 in an exploded state, and FIG. 3 is a cross-sectional view of the power element 8 manufacturing apparatus 200 in an assembled state.

2 and 3, the manufacturing apparatus 200 includes a housing body 210, a cover 220, a holding shaft 230, and an actuator (drive source) 240. Let X be the axis of the holding shaft 230.

The housing main body 210 includes a bottom wall 211 and a rectangular or cylindrical main body side wall 212 implanted in the bottom wall 211 . A circular opening 213 is formed in the bottom wall 211, and an opening 214 is formed in the main body side wall 212.

A glass plate GL is attached to the outside of the opening 214 via a holder 215 to cover the opening 214 . A packing PK1 is provided around the entire circumference between the opening 214 and the glass plate GL to seal the space between them. Any light transmitting member can be used other than the glass plate GL. Although not shown, a gas inflow hole and a gas discharge hole are formed in the housing body 210, and are connected to a gas source and a pump (not shown), respectively.

The cover part 220 has a top wall 221 and a square tube or cylindrical cover side wall 222 implanted in the top wall 221. The cross section of the cover side wall 222 is approximately equal to the cross section of the main body side wall 212. A circular opening 223 is formed in the top wall 221 . The housing body section 210 and the cover section 220 constitute a housing.

The holding shaft 230 has an upper shaft 231 and a lower shaft 235 that are separated from each other in the axis X direction. The lower shaft 235 includes a small cylindrical shaft 235a that is inserted through the circular opening 213 of the housing body 210 so as to be relatively rotatable, a large cylindrical shaft 235b having a larger diameter than the small cylindrical shaft 235a, and a hollow cylindrical shaft 235c. They are connected coaxially.

The lower end of the small cylindrical shaft 235a is rotatably connected to the actuator 240 outside the housing body 210. The small cylindrical shaft 235a has a groove 235d formed on its outer periphery, and an O-ring OR1 is disposed within the groove 235d. The O-ring OR1 has the function of sealing the small cylindrical shaft 235a when inserted into the circular opening 213.

The hollow cylindrical shaft 235c has a tapered upper end inner periphery and is formed with a communication hole 235f that communicates the inner and outer peripheries in the radial direction.

The upper shaft 231 coaxially includes a small cylindrical shaft 231a inserted through the circular opening 223 of the cover part 220 so as to be relatively rotatable, a large cylindrical shaft 231b having a larger diameter than the small cylindrical shaft 231a, and a hollow cylindrical shaft 231c. It will be installed consecutively.

The small cylindrical shaft 231a has a groove 231d formed on its outer periphery, and an O-ring OR2 is disposed within the groove 231d. The O-ring OR2 has the function of sealing the small cylindrical shaft 231a when inserted into the circular opening 223.

The hollow cylindrical shaft 231c has a tapered inner periphery at the lower end and is formed with a communication hole 231f that communicates the inner and outer peripheries in the radial direction.

(Power element assembly process)
Next, the assembly process of the power element 8 will be explained. First, as shown in FIG. 2, the housing body 210 and the cover 220 of the manufacturing apparatus 200 are separated, and the holding shaft 230 is separated into an upper shaft 231 and a lower shaft 235. At this time, the inside of the housing body 210 remains filled with the atmosphere.

In this state, the receiving member 86, the diaphragm 83, and the upper cover member 82 are placed and overlapped in this order on the upper end of the hollow cylindrical shaft 235c of the lower shaft 235. As a result, the outer periphery of the diaphragm 83 is held between the flange portion 86a of the receiving member 86 and the flange portion 82b of the upper lid member 82.

After that, the cover part 220 is fixed to the case main body part 210 while interposing the packing PK2 between the end of the main body side wall 212 of the case main body part 210 and the end part of the cover side wall 222 of the cover part 220. . As a result, the inside of the housing body 210 and the cover 220 are sealed from the outside (FIG. 3).

Therefore, while sweeping the air inside the main body part 210 and the cover part 220 with a pump through an exhaust hole (not shown), inert gas (N ₂ or He) is supplied to the housing from a gas source through an inflow hole. Inject into the main body part 210 and the cover part 220.

The inert gas injected into the housing body part 210 and the cover part 220 also enters the hollow cylindrical shafts 231c and 235c via the communication holes 231f and 235f, and further enters the gap between the receiving member 86 and the diaphragm 83. It also enters the inside of the dome portion 82a via the dome portion 82a.

When the inert gas in the housing body 210 and the cover 220 reaches a predetermined pressure, the upper shaft 231 is brought closer to the lower shaft 235 and pressed, thereby removing the receiving member 86, the diaphragm 83, and the upper lid member 82. The outer periphery of the rim should be tightly attached without any gaps.

While maintaining this state, a laser beam LB is emitted from an external laser light source (not shown), passes through the glass plate GL, and hits the flange 86a of the receiving member 86, the outer edge of the diaphragm 83, and the upper lid member 82. The light is focused on the overlapped portion with the flange portion 82b. This causes the temperature of the area where the light is focused to rise rapidly, causing the materials to melt and become integrated. At the same time, by rotating the holding shaft 230 that holds the receiving member 86 and the upper lid member 82 using the actuator 240, circumferential welding can be performed over the entire circumference of the joint between the flanges 86a and 82b. The holding shaft 230 may be rotated once while irradiating the laser beam LB, but stable welding can be performed by rotating it multiple times.

At this time, by spraying assist gas from the side of the condensing part of the laser beam LB, the metal vapor scattered from the heated area is deflected, and its aggregates adhere to the glass plate GL and reduce the transmittance. This can solve the problem of lowering the performance. Furthermore, by deflecting the scattering direction of the metal vapor by blowing the assist gas, it is possible to eliminate the problem that a part of the laser beam LB is blocked by the metal vapor and does not reach the condensing part.

By welding the joints of the flanges 86a and 82b, the upper lid member 82 and the diaphragm 83 are joined around the entire circumference, and the power element (to be welded) has a pressure working chamber PA sealed with inert gas at a predetermined pressure. Product) 8 is manufactured.

Thereafter, the interior of the housing body 210 and the cover 220 is filled with air while the inert gas inside the housing body 210 and the cover 220 is exhausted through the exhaust hole. The manufactured power element 8 can be taken out by separating the housing main body part 210 and the cover part 220 and separating the holding shaft 230 into an upper shaft 231 and a lower shaft 235 (see FIG. 2). The discharged gas can be reused after being subjected to predetermined processing.

In FIG. 1, when assembling the manufactured power element 8 to the valve body 2, the hollow cylindrical portion 86b of the receiving member 86 is inserted into the valve body while the upper end of the actuating rod 5 is fitted into the fitting hole 84c of the stopper member 84. Insert into the recess 2a of the main body 2. At this time, the space between the lower surface of the flange portion 86a of the receiving member 86 and the upper surface of the valve body 2 is sealed with the packing PK3. Furthermore, the power element 8 is fixed to the valve body 2 using a fastening member or caulking (not shown). A male thread may be formed in the hollow cylindrical portion 86b of the power element 8, and may be screwed together with a female thread formed in the recess 2a. In this state, the lower space LS of the power element 8 communicates with the return flow path 23, that is, has the same internal pressure.

According to this embodiment, there is no need to provide a hole in the upper lid member 82 for injecting inert gas into the pressure working chamber PA. Therefore, compared to the conventional process of providing a gas injection hole in the upper lid member and injecting gas into the pressure working chamber PA from there, the process of blocking the gas injection hole can be omitted, and manufacturing costs can be reduced. .

(Second embodiment)
FIG. 4 is a sectional view of a constant pressure valve 300 including a power element 380 according to the second embodiment.

The constant pressure valve 300 includes a valve body 320, a valve body 330, a biasing device 340, an actuation rod 350, a stopper member 360, and a power element 380. Let L be the axis of the constant pressure valve 300.

The cylindrical valve body 320 includes an annular portion 321 formed at the upper end, a concave valve chamber 322 formed at the lower end, and an actuation rod insertion passage 323 penetrating from the upper end to the valve chamber 322 along the axis L. A lateral hole 324 that intersects the operating rod insertion passage 323, a side wall opening 325 that connects the lateral hole 324 and the side surface of the valve body 320, and a communication hole that runs parallel to the operation rod insertion passage 323 and communicates the upper end of the valve body 320 with the lateral hole 324. 326. A valve seat 327 is formed on the outer periphery of the lower end of the operating rod insertion passage 323 .

One end of the outflow pipe 304 is fixed to the side wall opening 325 by brazing. The other end of the outflow pipe 304 is connected to an evaporator (not shown). The axis of the outflow pipe 304 is O.

The upper end of the inflow pipe 305 is inserted into the valve chamber 322 of the valve body 320 and fixed by brazing. The lower end of the inflow pipe 305 is connected to a condenser (not shown). The axis of the inflow pipe 305 coincides with the axis L of the constant pressure valve 300.

The power element 380 has an upper lid member (also referred to as a lid member) 382, a diaphragm 383, and a receiving member 386, and is used in combination with the stopper member 360.

The upper lid member 382 is formed by press-molding a plate material made of SUS, for example, and has a central dome portion 382a and a radial flange portion 382b that radially extends from the lower end of the dome portion 382a. The upper lid member 382 does not have a hole that communicates the upper and lower surfaces.

The diaphragm 383 is made of a thin metal plate on which a plurality of concentric concave and convex shapes are formed.

The receiving member 386 is formed by press-molding a plate material made of SUS, for example, and has a flange portion 386a that has approximately the same outer diameter as the outer diameter of the flange portion 382b of the upper lid member 382 and has a central opening 386b. There is. The power element 380 is attached to the valve body 320 by brazing the inner circumference of the central opening 386b of the receiving member 386 to the outer circumference of the annular portion 321.

A space surrounded by the upper lid member 382 and the diaphragm 383 forms a pressure working chamber PA, and a space surrounded by the diaphragm 383 and the receiving member 386 forms a lower space LS.

A stopper member 360 is arranged below the diaphragm 383. The stopper member 360 includes a disk 361 facing a diaphragm 383 and a cylindrical portion 362 connected to the disk 361. A fitting recess 363 is formed at the center of the lower surface of the cylindrical portion 362, into which the upper end of the actuating rod 350 is fitted.

The actuating rod 350 is inserted into the actuating rod insertion passage 323 of the valve body 320, and its lower end is in contact with the spherical valve body 330 within the valve chamber 322.

When the valve body 330 is in contact with (seats on) the valve seat 327, the opening is restricted and the inflow pipe 305 and the outflow pipe 304 are out of communication. On the other hand, when the actuating rod 350 moves downward to separate the valve body 330 from the valve seat 327, the inflow pipe 305 and the outflow pipe 304 are brought into communication. However, even when the valve body 330 contacts the valve seat 327, a limited amount of refrigerant may flow from the inflow pipe 305 to the outflow pipe 304.

Next, the urging device 340 will be explained. In FIG. 4, the biasing device 340 includes a coil spring 341 made of a circular wire wound helically, a valve body support 342 that is attached to the upper end of the coil spring 341 and supports the valve body 330, and a lower end of the coil spring 341. A spring receiving member 343 is attached to the valve body 320 while supporting the spring receiving member 343 , and is disposed within the inflow pipe 305 . The coil spring 341, which is a biasing member, biases the valve body 330 toward the valve seat 327.

The valve body support 342 has the function of supporting the valve body 330 on its upper surface and supporting the upper end of the coil spring 341.

The spring receiving member 343 is fixed to the inflow pipe 305 and supports the lower end of the coil spring 341, and has a function of not inhibiting passage of the refrigerant. Therefore, the spring receiving member 343 has a short circular tube shape and has an outer diameter smaller than the inner diameter of the inflow pipe 305. A circumferential groove 343a is formed at the center of the outer periphery of the spring receiving member 343.

(Assembling process of constant pressure valve)
The assembly process of the constant pressure valve 300 will be explained. The constant pressure valve 300 of this embodiment can be manufactured by a manufacturing apparatus 200A shown in FIG. 5. The manufacturing apparatus 200A differs from the manufacturing apparatus 200 of the embodiment described above only in the configuration of the lower shaft 235A of the holding shaft 230A. More specifically, the lower shaft 235A directly connects the hollow cylindrical shaft 235Ac to the small cylindrical shaft 235a, and the hollow cylindrical shaft 235Ac has a notch 235Ae extending from the upper end. The other configurations are the same as those of the manufacturing apparatus 200 described above, so the same reference numerals are given and redundant explanation will be omitted.

When assembling the constant pressure valve 300, first, the receiving member 386, the outflow pipe 304, and the inflow pipe 305 are brazed to the valve body 320, which has been machined into the shape shown in FIG. 4, and the assembly ASY (see FIG. 5) is assembled. ) to form.

Thereafter, with reference to FIG. 2, with the housing main body 210 and the cover 220 of the manufacturing apparatus 200A separated, and the holding shaft 230A separated into an upper shaft 231 and a lower shaft 235A, the assembly ASY, The diaphragm 383 and the upper lid member 382 are set on the lower shaft 235A in this order.

At this time, the inflow pipe 305 is housed within the hollow cylindrical shaft 235Ac, and the outflow pipe 304 is housed within the notch 235Ae. As a result, the outer periphery of the diaphragm 383 is sandwiched between the flange portion of the receiving member 386 of the assembly ASY and the flange portion of the upper lid member 382.

After that, the cover part 220 is fixed to the casing main body part 210, and while the air inside the casing main body part 210 and the cover part 220 is swept by a pump through a discharge hole (not shown), the air is supplied from a gas source through an inflow hole. Then, inert gas (N ₂ or He) is injected into the housing body 210 and the cover 220 .

The inert gas injected into the housing body 210 and the cover 220 also enters the hollow cylindrical shafts 231c and 235Ac via the communication holes 231f and 235f, and furthermore, enters the gap between the receiving member 386 and the diaphragm 383. It also enters into the dome portion 382a via the dome portion 382a.

When the inert gas in the housing body 210 and the cover 220 reaches a predetermined pressure, the upper shaft 231 is brought closer to the lower shaft 235A and pressed, thereby removing the receiving member 386, the diaphragm 383, and the upper lid member 382. The outer periphery of the rim should be tightly attached without any gaps.

While maintaining this state, a laser beam LB is emitted from an external laser light source (not shown) and transmitted through the glass plate GL, and the overlapped portion of the flange portion of the receiving member 386 and the flange portion of the upper lid member 382 is formed. Focus the light on. This causes the temperature of the area where the light is focused to rise rapidly, causing the materials to melt and become integrated. At the same time, by rotating the holding shaft 230 holding the assembly ASY using the actuator 240, circumferential welding can be performed over the entire circumference of the mating portion of the pair of flange portions.

The upper lid member 382 and the diaphragm 383 are joined around the entire circumference by welding the joints of the pair of flanges, resulting in an assembly (workpiece) having a pressure working chamber PA sealed with inert gas at a predetermined pressure. ASY is manufactured.

Thereafter, the interior of the housing body 210 and the cover 220 is filled with air while sweeping the inert gas inside the housing body 210 and the cover 220 through the exhaust hole. By separating the housing body 210 and the cover 220 and separating the holding shaft 230 into an upper shaft 231 and a lower shaft 235A (see FIG. 2), the assembly ASY including the manufactured power element 380 can be taken out. .

Next, the actuating rod 350 with the valve body 3 welded to its lower end is inserted into the actuating rod insertion passage 323 (FIG. 4) from the lower end of the assembly ASY, and is fitted into the fitting recess 363 of the stopper member 360. Further, the biasing device 340 is assembled into the inflow pipe 305 and the spring receiving member 343 is placed in a predetermined position. In this state, by hitting the outer periphery of the inflow pipe 305 with a punch or the like, the inner wall of the inflow pipe 305 fits into the circumferential groove 343a through plastic deformation, and the spring receiving member 343 can be fixed to the inflow pipe 305. .

Since the constant pressure valve 300 of this embodiment has a plurality of brazing locations, it needs to be heated in a brazing furnace. However, if the pressure working chamber PA is filled with inert gas before brazing, the pressure inside the pressure working chamber PA will increase due to heating during brazing, and there is a risk that the diaphragm 383 will be deformed and damaged.

On the other hand, according to the present embodiment, the constant pressure valve 300 is manufactured using the manufacturing apparatus 200A that can accommodate and hold the assembly ASY. Specifically, before filling the pressure working chamber PA with inert gas, a brazed assembly ASY is manufactured, and this assembly ASY is set in the manufacturing apparatus 200A, and the inert gas is filled into the pressure working chamber PA. Welding of the power element 380 is performed while enclosing active gas. This makes it possible to manufacture the constant pressure valve 300 while avoiding deformation or damage to the diaphragm.

(Operation of constant pressure valve)
An example of the operation of the constant pressure valve 300 will be described with reference to FIG. The refrigerant (fluid) pressurized by a compressor (not shown) is liquefied by a condenser and sent to the constant pressure valve 300 via an inflow pipe 305. The refrigerant discharged from the constant pressure valve 300 is sent to the evaporator, where it exchanges heat with the air flowing around the evaporator. Furthermore, the refrigerant that has passed through the evaporator is returned to the compressor side. In this way, the refrigerant circulates within the refrigerant circulation system.

High pressure refrigerant is supplied to the constant pressure valve 300 from a condenser. More specifically, the high-pressure refrigerant from the condenser enters the inlet pipe 305, passes through the spring receiving member 343, and reaches around the valve body 330.

In this embodiment, the lower space LS communicates with the refrigerant inlet of the evaporator via the outflow pipe 304. Therefore, depending on the pressure of the refrigerant flowing into the outflow pipe 304, the volume of the working gas in the pressure working chamber PA separated by the diaphragm 383 changes. When the internal pressure of the working gas in the pressure working chamber PA decreases, the working rod 350 is displaced upward together with the diaphragm 383 without being able to resist the biasing force of the coil spring 341, and the valve body 330 seats on the valve seat 327.

On the other hand, when the internal pressure of the working gas in the pressure working chamber PA increases, the working rod 350 is displaced downward together with the diaphragm 383 against the biasing force of the coil spring 341, and the valve body 330 is separated from the valve seat 327. In this way, the constant pressure valve 300 is switched between the open state and the closed state.

When the constant pressure valve 300 is in the open state, the refrigerant that has passed between the valve body 330 and the valve seat 327 enters the actuating rod insertion passage 323 and the side hole 324, and a part of it passes through the communication hole 326 and enters the lower space LS. The remainder is sent to the evaporator through the outflow pipe 304. In this way, in the constant pressure valve 300, the amount of refrigerant supplied from the constant pressure valve 300 toward the evaporator is automatically adjusted according to the pressure of the refrigerant returning to the evaporator.

Note that the present invention is not limited to the above-described embodiments. Variations in any of the components of the embodiments described above are possible within the scope of the invention. Moreover, any component can be added or omitted in the embodiments described above.

1 : Expansion valve 8 : Power element 100 : Refrigerant circulation system 101 : Compressor 102 : Condenser 104 : Evaporator 200, 200A : Manufacturing equipment 210 : Housing body part 220 : Cover part 230, 230A : Holding shaft 300 : Constant pressure valve 380 : power element

Claims (6)

A power element manufacturing device in which a diaphragm is sandwiched between a lid member and a receiving member,
A casing that can seal gas at a predetermined pressure inside and has an opening;
a light transmitting member that covers the opening;
a holding shaft that is disposed within the housing and holds the lid member, the diaphragm, and the receiving member in a stacked state;
a drive source that rotates the holding shaft;
a laser light source that performs welding by irradiating a laser beam from the outside of the casing to the overlapping portion of the lid member and the receiving member through the opening ,
The holding shaft has an upper shaft and a lower shaft arranged coaxially,
The upper shaft communicates with an upper shaft periphery that a peripheral edge of the lid member comes into contact with, an upper shaft recess formed at the center of the upper shaft periphery, and an outer periphery of the upper shaft and an inner periphery of the upper shaft recess. Has an upper shaft communication hole,
The lower shaft communicates with a lower shaft periphery that the peripheral edge of the receiving member contacts, a lower shaft recess formed at the center of the lower shaft periphery, and an outer periphery of the lower shaft and an inner periphery of the lower shaft recess. Has a lower shaft communication hole,
A power element manufacturing device characterized by: the gas is an inert gas;
The power element manufacturing apparatus according to claim 1, characterized in that: The housing is divisible along the rotational axis direction of the holding shaft.
The power element manufacturing apparatus according to claim 1 or 2, characterized in that: the lower shaft holds the receiving member brazed to other parts;
The power element manufacturing apparatus according to any one of claims 1 to 3, characterized in that: A method for manufacturing a power element in which a diaphragm is sandwiched between a lid member and a receiving member,
The upper shaft periphery has an upper shaft periphery that the periphery of the lid member comes into contact with, an upper shaft recess formed in the center of the upper shaft periphery, and an upper shaft communication hole that communicates the outer periphery of the upper shaft with the inner periphery of the upper shaft recess. an upper shaft, a lower shaft periphery with which a peripheral edge of the receiving member comes into contact, a lower shaft recess formed in the center of the lower shaft periphery, and a lower shaft communicating with the outer periphery of the lower shaft and the inner periphery of the lower shaft recess; holding the lid member, the diaphragm, and the receiving member in a stacked state in a housing using a lower shaft having a communication hole ;
Injecting gas at a predetermined pressure into the housing,
While rotating the lid member, the diaphragm, and the receiving member, welding is performed by irradiating the overlapped portion of the lid member and the receiving member from outside the housing with a laser beam, thereby welding the object to be welded. form,
discharging the gas in the casing and taking out the workpiece from the casing;
A method for manufacturing a power element characterized by: A method for manufacturing a power element according to claim 5, comprising:
The lid member is formed from a plate material that does not have a hole that communicates between opposing surfaces.
A method for manufacturing a power element characterized by:

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